Re: Performance Tuning Question

Поиск
Список
Период
Сортировка
От Andrew Sullivan
Тема Re: Performance Tuning Question
Дата
Msg-id 20020909131858.K15959@mail.libertyrms.com
обсуждение исходный текст
Ответ на Re: Performance Tuning Question  (Brian Hirt <bhirt@mobygames.com>)
Список pgsql-general
On Mon, Sep 09, 2002 at 09:41:30AM -0600, Brian Hirt wrote:
>
> I know this, but i cannot find any good reference how to tune them and
> how changing them.

[. . .]

> FYI: I did set effective_cache_size to 1.5gb, but the estimated cost for
> the query using the index remained exactly the same.

You probably want to twiddle CPU_INDEX_TUPLE_COST (floating point)
and RANDOM_PAGE_COST (floating point).  But note what the docs say
about these items:

Note: Unfortunately, there is no well-defined method of determining
ideal values for the family of "COST" variables that were just
described. You are encouraged to experiment and share your findings.

If you have any luck, it'd be nice to know what you discover.

A

--
----
Andrew Sullivan                         204-4141 Yonge Street
Liberty RMS                           Toronto, Ontario Canada
<andrew@libertyrms.info>                              M2P 2A8
                                         +1 416 646 3304 x110


В списке pgsql-general по дате отправления:

Предыдущее
От: Tom Lane
Дата:
Сообщение: Re: AutoCommit mode in PostgreSQL (7.3 beta1 from CVS 05.09.2002)
Следующее
От: Andrew Sullivan
Дата:
Сообщение: Re: Load sharing question